Study On The Ultrasonic Scale Effect Of Ultrasonic Assisted Micro Plastic Forming

During the process of traditional metal micro plastic forming,because of the influence of size effect in micro forming process,thus the friction of preform body in forming process is enlarged,and the forming property is reduced.While ultrasonic auxiliary micro plastic heading extrusion forming process combines is a kind of forming method with ultrasonic mechanical vibration energy,which makes preform body generate micro plastic deformation under loading action.During the process of ultrasonic auxiliary micro plastic heading extrusion forming,ultrasound effect can reduce the material flow stress,so as to improve the contact condition among workpiece molds.This paper introduces ultrasonic vibration into the process of micro plastic forming,then it combines experimental study and simulated analysis,thus studies the influence of ultrasonic vibration on material deformation rule when the material deformation size is smaller.For the process of ultrasonic auxiliary micro heading extrusion forming,this paper designs and constructs floating type ultrasonic auxiliary heading extrusion forming device,so as to study the influence of ultrasonic amplitude on material deformation during the process of ultrasonic auxiliary heading extrusion forming,and ultrasonic auxiliary micro ultrasonic scale effect in the process of upset.Studies show that:(1)using floating experiment device for ultrasonic assisted upsetting,forming the shape and stationary experiment device of the proceeds of the forming of the workpiece are obviously different,ultrasonic assisted upset experiments show that shows that experiment device of floating type forming workpiece holes filling ability better.(2)ultrasonic vibration could improve the ability of the workpiece forming,significantly improved the shape of the workpiece material flow.In addition,ultrasound assisted upset forming surface to appear black substance,and along with the increase of amplitude,the phenomenon is more obvious.(3)the micro plastic forming process,with the decrease of the billet diameter((1.5 mm to 0.5 mm)),the flow of material is more difficult,a significant size effect,material extrusion length is obvious more and more small,and the blank size is smaller,the more obvious size effect.After the introduction of ultrasonic vibration,can be found,along with the size of workpiece forming,material forming ability increases,ultrasonic vibration material filling ability of holes are increased obviously,improved the material the size effect of micro plastic forming process.(4)based on the relative increment of characterization of ultrasonic upsetting extrusion process of ultrasonic scale effect study has found that relative to the tooling holes the relative increment of 1.5 mm in diameter,die hole diameter of 1 mm,0.8 mm and 0.5 mm relative increment increases significantly,in ultrasonic auxiliary micro plastic forming process,the ultrasonic vibration significantly higher material forming ability,there is an obvious ultrasonic scale effect.This paper adopts finite element simulation technology,so as to study the forming mode and material deformation rule of workpiece during the process of ultrasonic auxiliary micro heading extrusion forming: based on material deformation equivalence principle,it adopts simulation technique to study the influence of material strain softening effect and friction reducing on forming process.The study shows that only applying the two cannot simulate the effect of ultrasonic vibration on micro hole filling ability improvement.